Quartz glass, quartz glass products and products which contain quartz glass are known. Likewise, various processes for the preparation of quartz glass, quartz glass bodies and grains of quartz glass are already known. Nonetheless, considerable efforts are still being made to identify preparation processes by which quartz glass of even higher purity, i.e. absence of impurities, can be prepared. In many areas of application of quartz glass and its processed products, high demands are made, for example in terms of purity. This is the case, inter alia, for quartz glass which is provided for an application in production steps in the fabrication of semiconductors. Here, every impurity of a glass body can potentially lead to defects in the semiconductor and thus to rejects in the fabrication. The varieties of high purity quartz glass which are employed in these processes are therefore laborious to prepare. These are valuable.
Furthermore, there is a market requirement for the above mentioned high purity quartz glass and products derived therefrom at low price. Therefore, it is an aspiration to be able to offer high purity quartz glass at a lower price than before. In this connection, both more cost-efficient preparation processes as well as cheaper sources of raw materials are sought.
Known processes for the preparation of quartz glass grains comprise melting silicon dioxide, making quartz glass bodies out of the melt and reducing the size of the quartz glass body to a grain. Impurities of the glass body made at the outset can lead to a failure of an opaque glass body made from the grain under load, in particular at high temperatures, or can preclude its use for a particular purpose. Impurities in the raw materials in the opaque glass body can also be released and transferred to the treated semiconductor components. This is the case, for example, in etching processes and leads to rejects in the semiconductor billets. A common problem associated with known preparation processes is therefore an inadequate quality of the purity of quartz glass bodies.
A further aspect relates to raw materials efficiency. It appears advantageous to input quartz glass and raw materials, which accumulate elsewhere as side products, into a preferably industrial process for quartz glass products, rather than employ these side products as filler, e.g. in construction or to dispose of them as rubbish at a cost. These side products are often separated off as fine dust in filters. The fine dust brings further problems, in particular in relation to health, work safety and handling.